U.S. Pat. No. 4,726,615 to Goldberg includes a disk handling tool having a central plunger and two flexible arms. The central plunger inserts into a disk. Actuation of the central plunger spreads the arms around the outer edge of the disk. As the disk handling tool lifts, the arms automatically grip the disk on edge. The Goldberg tool is particularly suited to moving single disks to and from standard CD cases because the central plunger can actuate by pressing against the case. The Goldberg tool would be less viable when separating disks from a stack of disks where no disk case is present.
U.S. Pat. No. 5,505,509 to Vance includes a tool having a trigger, a spindle catch and a soft curved cup. Each disk has a central opening. The spindle catch inserts through the opening and aligns axially with respect to the disk. Actuation of the trigger axially misaligns the spindle catch. The disk is held between the spindle catch and the soft curved cup. One drawback of this tool is that because the spindle catch must insert through the disk, the Vance tool does not efficiently separate disks from a stack of disks.
U.S. Pat. No. 5,692,87 to Freund discloses a disk handling system which separates disks from a stack of disks. The Freund system is a double-gantry system. The double gantry system includes a lifting means, tapered shaft, a spring arm and a gripper.
The tapered shaft inserts centrally within a stack of disks. The spring arm is fixed relatively above the stack. The lifting means vertically lifts the stack against the spring arm. The spring arm offsets the uppermost disk from top of the stack. The gripper grasps the edge of the offset disk by its edge to move the disk from the top of the stack.
Double gantry systems, in general, have a large number of moving parts. These parts must be coordinated. The probability of wear and malfunction typically increases with each additional moving part. What is desired is a simple system which operates without much adjustment, and which reliably dispenses disks from a stack of disks.